Incandescent tubular lamp



July 25, 1939- E. sPlELHoLz INCANDESGENT TUBULAR LAMP- Filed Nov. 8, 1938 Patented July 25, 1939 PATENT oFF-1er:

INCAND'ESCENT TUBULAR LAMP Emanuel Spielholz, North Bergen, N. J., assignor to Duro-Test Corporation, a. corporation of New York Application Nvember 1s, 193s, serial No. 241,263

Claims.

This invention is a novel improvement in incandescent tubular lamps, and the principal objects thereof are to provide a lamp of elongated tubular form, having a pair of incandescent fila- 5 ments mounted upon elongated supports disposed at the ends of the body, the laments themselves Ahowever being positioned near the center of the body, and said filaments being connected in a circuit leading from a single threaded plug or head of the lamp, the conductors between the filaments extending within the body through insulating tubes of glass or the like, which tubes are secured at spaced intervals by fusing to the inner wall of the lamp body, whereby the conductors will be properly protected by the glass tube insulators, and the arrangement of the latter will minimize any deleterious effect upon the illuminating qualities of the lamp.

I will explain the invention with reference to 20 the accompanying drawing which illustrates one practical embodiment thereof to enable others familiar with the art to adopt and use the same, and will summarize in the claims the novel features of construction, and novel combinations of parts, for which protection is desired.

In said drawing:

Fig. l is a longitudinal section through an incandescent tubular lamp according to my invention.

Fig. 2 is a section on the line 2 2, Fig. 1.

As shown, the lamp comprises an elongated tubular body I having its outer end closed, and its inner end contracted and provided in the customary manner with a threaded plug or head 2. Within the tubular body I at each end thereof are elongated supports 3 extending axially of the body and carrying on their inner ends incandescent ilaments 4 ands of tungsten or the like, the iilaments being spaced apart but disposed adjacent the center of the lamp rather than at the ends thereof, thereby increasing the luminating qualities of the lamp. Both filaments 4 and 5' are connected electrically with the threaded plug or head 2. The iilament 4 adjacent the threaded plug is directly connected by Wires 5, 5a to the customary terminals of the plug, and the iilament 5 is connected by wires 6, 6a, which are connected directly with the wires 5, 5a, respectively, of the filament 4.

The wires 6, 6a extend within the body I and are protected by insulating tubes 'I of glass or other transparent insulating material diametricallydisposed within the lamp body, and preferably extending substantially the full length of the body I, whereby the wires Will be properly supported. Each of the insulating tubes 'I is connected directly to the inner wall of the lamp body at spaced points by fusing, as at Ia (Fig. 2).

The tubular body I is sealed at both ends, and as is customary the'air in the body before sealing may be removed from an exhaust duct 8 at the end adjacent the plug or head, which duct after the air has been exhausted is sealed to maintain the vacuum.

The above construction provides a simple and eiiicient construction in which the incandescent iilaments 4 and 5 and the conductor wires 6, 6a, are properly protected from destruction while handling or in use; and at the same time provides a lamp having a single threaded plug or head 2 to which each of the laments are electrically connected, the filaments themselves, of the ordinary incandescent type, being supported adjacent the central portion of the tube.

I claim:

1. An incandescent electric lamp, comprising a substantially tubular body closed at one end; a contact plug closing the other end of the body; supports within the body at the ends thereof; incandescent filaments on said supports; conductor wires connecting said iilaments respectively With the said plug; and insulating tubes carrying the wires for the filament remote from the plug and connected to the wall of the body.

2. An incandescent electric lamp, comprising an elongated substantially tubular body closed at one end; a contact plug closing the other end of the body; supports within the body extending from'the ends thereof; incandescent filaments on said supports; conductor Wires connecting said iilaments respectively with the said plug; and insulating tubes `carrying the wires for the lament remote from the plug, said tubes being diametrically opposed and fused at spaced points to the wall of the body.

3. An incandescent electric lamp, comprising an elongated substantially tubular body closed at one end; a contact plug closing the other end of the body; elongated axially disposed supports within the body extending from the ends there of incandescent filaments on said supports disposed in spaced relation adjacent the center of the body; conductor wires connecting said filaments respectively with the said plug; and insulating tubes housing the wires for the filament remote from the plug and connected to the inner wall of the body.

4. An incandescent electric lamp, comprising an elongated substantially tubular transparent body closed at one end; a threaded plug closing the other end of the body; elongated axially disposed supports Within the body extending from the ends thereof; incandescent filaments on said supports disposed in spaced relation adjacent the center of the body; conductor wires connecting said laments respectively with said plug; and transparent insulating tubes housing the wires for the lament remote from the plug, said tubes being diametrically opposed and fused at spaced 10 points to the inner wall of the body. 

